Blow molded plastic bottles are well known and come in a variety of sizes and shapes to contain a wide variety of liquid, commercial and consumer products. While many bottles are boxed in cases or cartons for shipment, in more recent years attention has been paid to designing bottles which have sufficient strength so as to not require the protection and support afforded by other packaging materials. The containers of the present invention are designed to be stacked on a pallet and held in place by means of shrink-wrap applied to the pallet and containers.
Blow molded containers of consumer products are often used to construct point of sale displays involving multiple layers of the containers. It is therefore necessary that the containers have the required strength and stability to be stacked and thereby present to the purchasing public an attractive yet safe and stable display. The preferred embodiment of the present invention is intended to be so constructed as to require that each layer of stacked containers be rotated about a vertical axis by 90.degree. and thereby display more than a single face or side panel of the container to the prospective purchaser.
A container constructed in accordance with the present invention has a unitary body formed of a thermoplastic material such as high density polyethylene. Other materials suitable for use in forming such a container include the whole range of thermoplastic resins usable in blow molding. The container is molded in the form of a unitary body having a bottom surface, a sidewall, and a top surface including an opening which can be closed by a cap or other closure means. In the preferred embodiment, the closure is a screw threaded plastic cap of conventional design which can be used to open and re-seal the container any number of times.
The bottom surface of a container constructed in accordance with the present invention has a recessed portion which includes a web-like external rib depending downwardly within the recessed portion. The web-like external rib can be formed by the pinch-off of the extruded parison. The top surface of the container according to the present invention includes notch means for receiving the external rib of a geometrically similar container stacked thereon so as to laterally locate and stabilize the relative positions of the stacked containers.
In a preferred embodiment the recess portion of the bottom surface of the container includes a release groove bifurcating the bottom surface of the container. The external rib intersects the middle of the release groove. The top surface includes a handle to permit the container to be lifted and carried. The notch means is preferably situated on a upper surface of the handle.
One feature of the present invention is the existence of a notch means on the top surface of a container for receiving a web-like external reinforcing rib located on the bottom surface of a geometrically similar container. The receiving of the external reinforcing rib on the bottom surface of an upper container into a notch means on the top surface of a lower container causes the containers to be laterally located and stabilized with respect to each other thereby permitting the containers to be more readily stacked for shipment and display.
Another feature of the present invention is the formation of the rib within a recess bifurcating the bottom surface of the container the recess being of such a size that no substantial vertical loading of the container occurs in the region of the rib. This has the advantage of locating a major proportion of the vertical loading on the portion of the bottom which straddles the recess thereby distributing the vertical load over a larger area and reducing local stress to the container.
Yet another feature of the present invention is the location of the web-like external reinforcing rib on the bottom surface and notch means on the top surface such that they are arranged orthogonally with respect to each other. Such orthogonal arrangement has the advantage of requiring that the bottles be axially rotated with respect to each other when stacked so as to permit a better display of labels and other external indicia which might appear on the bottles.
Other features and advantages of the present invention will become apparent to those skilled in the art upon consideration of the following detailed description of a preferred embodiment exemplifying the best mode of carrying out the invention as presently perceived.